The present invention relates to a method for examining a value document and to a corresponding apparatus for carrying out the method.
Value documents are understood here to be sheet- or card-shaped objects that represent for example a monetary value or an authorization and hence should not be manufacturable arbitrarily by unauthorized persons. Such value documents have features that are not easily manufactured or copied, whose presence is an indication of authenticity, i.e. manufacture by an authorized body Important examples of such value documents are chip cards, coupons, vouchers, checks and in particular bank notes.
Certain value-document types have, as a humanly recognizable security feature, a window which has a special optical property compared to other portions of the value document, for example elevated transparency or translucency.